Pneumatic tire carcass construction

ABSTRACT

Unique carcass constructions and tires containing same, the carcass featuring variant cord angles depending upon the location of the cord in the carcass, are disclosed herein together with novel sheet-like candidate materials for carcass plies and methods of making such sheet-like materials featuring these variant angles.

This is a division of co-pending application Ser. No. 811,930, filedApr. 1, 1969, now U.S. Pat. No. 3,675,702.

The present invention relates to pneumatic tires and more particularlyto a unique carcass construction and a method of making same.

Tires and, as well, many other industrial rubber products include,interiorly thereof, various textile materials as a strengthener orreinforcement. The most prominent and conventionally used textiles forthis application up to the present time include cotton, rayon, thevarious polyamides, e.g., nylon, and the polyesters such as DACRON.Steel wire has been used in some special heavy duty applications. Morerecently, glass in the form of yarns, strands and cords has been someuse as a tire reinforcement and, as well, a reinforcement of otherindustrial products.

As a candidate reinforcement for tires, glass may be considered ashaving a number of desirable filament properties. A glass filamentpossesses essentially 100% elasticity, demonstrates essentially no yieldunder stress, demonstrates excellent dimensional stability and isvirtually immune to changes in atmospheric conditions; amongst which themost important are moisture and heat from the standpoint of theconsideration of glass as a reinforcement for tires.

At the same time, it has been found that the mere substitution of glassfilaments, or yarns and strands formed of gathered-together glassfilaments, for strands, yarns and cords of the more conventional textilematerials in and for reinforcement for tires and other industrialproducts does not yield a tire or other industrial product which isdemonstrative of the improvement one might expect for the desirableproperties hereinabove enumerated. The reasons for this are suspected tobe quite numerous. A rational review and consideration of glass overallsuggests a number of the reasons why a plain substitution of glass forthe other more conventional reinforcements is not possible. Thus, glassis possessed of a considerable stiffness as compared to the other moreconventional materials. The stiffness of glass is 322 grams per denier(gpd). For purposes of comparison, it may be noted that nylon has astiffness which ranges from 18 to 23 gpd, while the polyesters rangefrom 11 to 21 gpd, the acrylics such as ACRILAN and ORLON range from 7to 10 gpd and viscose rayon varies from 11 to about 25 gpd. Theelongation of glass at break is in the order of 3-4%. In contrast, thevarious polyesters range anywhere from 19-30%, the nylons range from16-40%, the acrylics from 36-40% and viscose rayon anywhere from 9-30%,depending upon the particular type and brand. Of not inconsiderableimportance is the fairly high specific gravity of glass. Glass has avalue of 2.54 compared to nylon's 1.14 rayon's 1.5 and polyesters suchas KODEL and DACRON which range from 1.22 to 1.38. Glass is also notnearly as tough on a denier basis as the other materials. The abovevalues illustrate a considerable variance in a number of propertieswhich are important and have an effect on the use of glass as areinforcement material.

Accordingly, it is an object of the present invention to provide atechnique including a particular geometric, e.g., spatial, location ofglass within the body as will enable the utilization or maximization ofits desirable properties and a minimization of its less desirableproperties which have been set forth.

It is a particular object of the present invention to provide a tireconstruction featuring a carcass ply structure formed of glass cords orstrands so arranged as to permit the attainment of the foregoing object.

It is additionally an object of the present invention to provide a tireconstruction of the pneumatic type which features a plurality of carcassmembers which differ in terms of the cord alignment and orientation invarious segments thereof.

It is also another object of the present invention to provide a novelcalendered sheet good containing mutually parallel but of inconstantangular relationship.

It is a special object of the present invention to provide a tireconstruction inclusive of carcass ply cords which embody and combinefeatures of a radial construction and at the same time features of abias construction.

It is also an object of the present invention to provide a method and anapparatus for producing the carcass ply members featuring the variantangle reinforcing cords as described more in detail hereinafter.

It is also an object of the present invention to provide a tire whichfeatures an interior carcass reinforcement construction which is ofsemi-radial cord orientation whereby blurbing and/or distortion at theedge of the tire as frequently observed in radial tires is avoided.

It is still another object of the present invention to provide a tirecarcass construction which features a continuous curvilinear cord havingsegments which define generally bias angle in the side wall andgenerally a radial angle in the tread region of the tire.

it is yet another object of the present invention to provide novelmethods of producing a carcass construction having the featuresdescribed in the immediately preceding object.

The foregoing and, as well, other objects of the present invention willbecome apparent to those skilled in the art from the following detaileddescription taken in conjunction with the annexed sheets of drawings onwhich there are presented several embodiments of the present inventiononly in the interest of illustrating same.

IN THE DRAWINGS

FIG. 1 is a perspective view of a tire in accordance with the presentinvention; parts of the tire being broken away to more clearly show theinterior of the tire and parts of the carcass components being shown indotted outline;

FIG. 2 is a perspective view similar to FIG. 1 illustrating a tireconstruction in accordance with another embodiment of the presentinvention;

FIG. 3 is a plan view of a carcass ply having a construction inaccordance with the present invention;

FIG. 4 is a plan view of a carcass ply illustrating another embodimentof the present invention;

FIG. 5 is a plan view of an elongate sheet material illustrating theformation of a carcass ply;

FIG. 6 is a schematic perspective view of apparatus in operationproducing a mat-like structure of utility as a component of a carcassconstruction for a tire;

FIG. 7 is a plan view of an elongate sheet with a portion broken away toshow an interiorly disposed continuous cord arranged in repeating loopsschematically illustrating the arrangement of the segments of the loopin different regions of a carcass ply into which the sheet may bedivided for use as a tire body member; and

FIG. 8 is a sectional view of a tire construction including carcassplies formed of the sheet material according to FIGS. 6 and 7.

Viewed most simply, the present invention envisions a tire constructionin which the carcass plies individually will be composed of cords,preferably of gathered-together filaments of glass; the cords having abias angularity in the ultimate side wall region of the tire and havingradial angularity in the tread or crown region of the ultimate tireconstruction.

Reference may now be had to the drawings for a more detailed descriptionand explanation of the invention herein concerned.

In FIG. 1, the tire 11 is cut away on the line 13 to reveal a lowercarcass ply 15, an upper carcass ply 17, a lower belt ply or breakerstrip 19 and an upper belt ply or breaker strip 21. The tire 11 includesspaced beads 23 and 25, a shoulder region 27 and a ground contactingtread 29. In accordance with the present invention, the lower carcassply 15 is composed of a plurality of cords 15a which have their one endturned up about bead 23 as at 15b, extend at a bias angle up to theshoulder region as at 15c, thence on the shortest path directly acrossthe tread to the opposite shoulder region as at 15d, then downwardly atthe same bias angle as on the other side to the head 23, specificallythe "turn up" as at 15d.

It will be appreciated that, viewing the tire in side elevation, theside wall segments of the cord 15a, and all the other cords making upthe carcass ply 15, would appear in registration, one with the other.The upper carcass ply 17 is made up of a plurality of side-by-sidecarcass cords (see cord 17a) which are similar to the carcass cords 15ain the lower carcass 15 excepting that the segments of the cord in theside wall region, that is, extending from the beads to the shoulderregion, define an angle which is approximately equal to but opposite tothe angle defined by the same segment of the cord 15a in its path fromthe bead to the shoulder region. The relative angularity of these plycords in the side wall region is illustrated by the dotted linerepresentation of these two ply cords 15a and 17a. The cords 17a (onlyone is shown in the interest of clarity), of which outer carcass ply 17is composed, may be described as hoop-shaped, as reference to thedrawings will reveal. It may also be noted that the side wall and treadsegments of the hoop defined by cord 17a, considered together, define animaginary plane which is oppositely inclined to the imaginary planedefined by the connected tread and side wall segments of cord 15a.

In FIG. 2, the tire 31, which also has a segment cut away to show theinterior, is composed of spaced beads 33 and 35, a connected toroidalcarcass extending therefrom through shoulder region 37 and the treadregion 38. The carcass is composed of a lower carcass ply 41 and anupper carcass ply 43, above which and extending from shoulder toshoulder are a pair of tread reinforcing belt plies 45 and 47.

Reference numeral 43a identifies one of the cords of which the upper orouter carcass ply 43 is composed, while reference numeral 41a identifiesone of the plurality of identical cords of which the lower carcass ply41 is composed. The cord 41a, as can be seen, has its end extremitieslooped around the beads 33 and 35. Commencing at the bead 35, the cord41a proceeds up the side wall toward the shoulder at an angle, generallyindicated by the direction of the arrow 48, thence from the shoulderregion, identified by the reference numeral 41b, directly across thetread region of the tire to the shoulder 37 and then downwardly at anangular direction, generally indicated by the arrow 48, to the bead 33and is wrapped thereabout. The segments of the cord 41a which reside inthe side wall region are oppositely inclined, while the center segmentof the cord 41a in the tread region extends in a radial manner acrossthe tread which may be described as at a 90° angle of the peripheralcenter groove of the tread (not shown).

The outermost ply 43 is composed of a plurality of side-by-side cords,of which cord 43a is representative. Cord 43a is very similar to thecord 41a excepting that the segments thereof extending from the bead tothe shoulder region are oppositely inclined in a given side wall. Thisis clearly illustrated in FIG. 2. The cords making up the carcass pliesin accordance with the embodiment of FIG. 2 are not hoop-shaped and donot define an imaginary plane since the side wall segments thereofextend in opposite directions from the shoulder region of the tire.

The carcass ply 15 is shown in plan view of FIG. 3 prior to beingincorporated into the tire 11. As can be seen, a plurality of mutuallyparallel cords 15a, embedded in an elastomeric matrix by calendering,extend from edge 15f (ultimately forming a bead region of the tire) tothe edge 15g (ultimately forming the opposite bead region). The cordsextend angularly from one edge 15a to a center section (alternatelylying in the tread region) where the cords change direction to extenddirectly thereacross and thence at a reverse angle back to the otheredge. The carcass ply is bias cut, as indicated, in order that it may beincorporated onto the tire building drum in accordance with the flatband technique of tire building.

The carcass ply 41 of the tire of FIG. 2 is shown in plan view in FIG.4. As may be readily seen, the distinction between it and ply 15 residesin the fact that the cords in the side wall segment are in generallyparallel relationship, whereas in the side wall regions of the carcassply 15 the cords are not in parallel relationship.

A tire construction featuring carcass plies having the cordconfiguration as disclosed in FIG. 1 is preferred in accordance with thepresent invention. The tires illustrated in both FIGS. 1 and 2 employtwo carcass plies. It is, of course, desirable under certaincircumstances, and particularly in larger truck tires, to employ morethan two plies in the carcass region. Tires in accordance with thepresent invention may embody only carcass plies of the type described orthe tire may feature, in combination therewith, belt plies asillustrated in the drawings. The belt plies are desirably formed of aband of elastomeric material containing a plurality of side-by-sidemutually parallel bundles of glass filaments; the belt or band being sofabricated that the bundles or cords of glass proceed in one directionin one belt ply and in an equal but opposite direction in the other beltply.

Cords for the various carcass plies and belt plies as describedhereinabove are most desirably formed of a gathered-together pluralityof strands, each of which is composed of either a gathered-togetherplurality of yarns, each of which is composed of a plurality ormultiplicity of individual glass filaments, or the strands themselvesmay be formed of a multiplicity of individual continuous glassfilaments. The number of filaments in a given cord may range fromseveral hundred to several thousand in number. A particular attribute ofa tire constructed in accordance with the present invention resides inthe improved rolling stability by reason of the inclination of themultiplicity of cords directly across the tread in the radial directioncoupled with the bias angularity of the same cords in the side wallregions of the tire. The foregoing, in combination with treadreinforcing belts fabricated of glass cords, lends a unique stability ofthe tire tread in terms of resistance to squirming and movement undercornering and braking service conditions.

It is a significant feature of the tire construction of the presentinvention that they do not exhibit the troublesome phenomenon ofblurbing and edge distortion which is exhibited by the conventionalradial tire. In the tire, the cords of the principal carcass ply extendin the shortest path from the bead to the adjacent shoulder, thenceacross the crown and thence in the opposite side wall in the shortestpath to the opposite bead. The cord ends are thus directly across fromeach other in the bead region. Viewed in another way, the individualcords define a loop which is the shortest possible in a given tire size.By reason of this structure, it is believed that under dynamiccondition, e.g., under load and rolling, the cords in the shoulder andside wall are placed in compression as the tire rotates, specifically asthe given cord is deflected during its passage through that arc ofrotation in which the segment of the tire is in contact with the road.

With the construction of the present invention, any given cord end isanchored in the bead at a point which is angularly displaced from thecentral portion of the cord which is being exposed to the forcesgenerated as the tread region (in which the central portion is located)is experiencing deflection in passing in load-bearing contact with theroad. Consequently, the cord being deflected in the tread and shoulderregion does not transmit this compressive forced directly to theremainder of the cord as in the case of a fully radial cord, but rathersuch forces have an opportunity for dissipation or absorption due to theangular orientation of the cord in the side wall region. The angularlydisposed cord (taken with reference to a radial cord) is, of course,embedded in a matrix of rubber which is supporting the cord along itsgreater length as compared to the radial cord.

Reference to FIG. 5 reveals a segment of an elongate vulcanizable stripmaterial identified by the reference numeral 50. As can be seen, theelongate strip material includes three serially connected segments 51,52 and 53; all of which contain within the segment mutually parallelcords which, however, proceed collectively in different directions inthe three segments. The cords within the segment 52 which corresponds tothe ultimate tread region of the ply extend in horizontal directionwhich conforms to a 90° or radial angle and which at the same time is inthe plan view perpendicular to the bend regions of the tire which arerepresented by the edges 54 and 55. Lines 57 and 59 identify the biascutting of the elongate strip as to yield a carcass ply adapted forincorporation into the "flat band" tire building operation. The latterbeing well understood in the art, it will not be described in detailherein.

The carcass plies as illustrated in FIGS. 3, 4 and 5 and featuringvariant cord angles can be produced by employment of a suitable jig.Thus, a sheet in which the cords are of uniform parallel orientation islocated in an arrangement provided with appropriate means controlled togrip the sheet and also with auxiliary means suitably movable to shiftthe parallel cords into the orientation as shown in any of FIGS. 3 to 5.

Naturally, the selection of the precise angle in the various segments ofthe carcass ply is, in part, dependent upon the particular tire size,the characteristics, e.g., toughness and/or plasticity, of theparticular rubber stock and the amount of pantographing which will occuras the band is expanded to final tire configuration during the Bagomaticcure cycle. Thus, it is known that the "green" angle described by agiven tire cord, that is, the angle of the cord considered in itsposition on the tire building drum (before vulcanization), will notnecessarily be the same as the "cured" angle, that is, the angle of thecord taken with reference to a reference point, usually the peripheralcenterline, after the "green" tire has been expanded into the mold inthe vulcanization process, usually in the referred-to "Bagomatic" curingprocess. Thus, the "green" tire which may be described as approximatelythe configuration of a beer barrel is in an unvulcanized state. In thevulcanizing operation, during which the beer barrel configuration isconverted into the conventional tire configuration, the "green" beerbarrel shaped member is placed in a lower mold half, defining one-halfof the tire. At the same time, and expandable casing approximately aninner tube is located inside of the beer barrel. Thus, it is expanded bysteam pressure pushing the central region of the beer barrel shapedmember outwardly as an upper mold half desends, closing the mold. Theinner casing approximately an inner tube thus pushes the "green" tirecomponent radially outwardly whereby the outer exterior thereof takes onthe side wall and tread configuration which is defined by the interiorsurface of the tire mold halves. Thereafter, of course, the tire isremoved after appropriate heat conditioning. Since the end extremitiesof the given cords of the carcass plies are held relatively immobile inthe bead region, the cords in extending through the side wall region,the tread region and the opposite side wall region experience somerealignment. Obviously, this shift in "green" angle to "cure" angle is apredetermined factor or can be determined with limited trial and can betaken into account in choosing the appropriate angles in the segments ofthe carcass plies. For purposes of simplicity, the cord angles in thebias plies as illustrated in FIGS. 3, 4 and 5 have been represented asthe ultimate desired. Thus, it can be seen that in the tread segment thecords proceed diametrically across the tread in a radial direction. Asindicated, the actual "green" angle of this cord in this segment may notbe exactly diametrically across since the cord may experience some shiftdue to the pantographing of the cords.

Reference may now be had to FIGS. 6 and 7 wherein further embodiments ofthe present invention are illustrated. FIG. 6 illustrates apparatus andmethod for producing an essentially nonwoven mat of continuous strandmaterial disposed in a manner as provides, when incorporated into arubber matrix, an elongate sheet of utility in forming a carcass plycharacterized principally by an interior cord or strand angle which isof preselected variable angle. The angle of the strand material can becontrolled, in a manner to be described, as to yield in the carcass astrand angle which in the ultimate tread region of the tire, in whichthe carcass is incorporated, will be generally radial while the angle ofthe cord, generally in the region of the carcass which essentiallyconstitutes the side wall region of the tire in which ultimatelyincorporated, will be generally angular or of bias inclination.

As indicated, the apparatus and method is schematically illustrated inFIG. 6. A conveyor 100 is controlled to pass beneath an overheaddispenser 102. The dispenser comprises an outer housing 104 which isgenerally hollow and contains therewithin a member 106 mounted onbearings 108 in a manner as to be rotatable. The cord or strand 110passes vertically downwardly through an entry aperture 112 in thehousing 104, through a tubular passageway 114 in the rotating member 106to the dispenser tube 116 mounted at the bottom thereof. The latterpreceeds downwardly and then at an angle terminating in an outlet end118. A lateral tube 120 connects with the housing 104 and a suitableopening connects this tube fluidly with the passageway 122. A fluidmedium such as air is introduced through the tube 120, passes throughthe passageway 122, thence down through the passageway 114 through thelower dispenser tube 116 and out the outlet 118 carrying the strandmaterial with it. At the same time, the member 106 is rotated, causingthe outlet tube 116 to move in a circular path as indicated by the arrow124. The rotation of the member 106 and tube 116, the velocity of theair and the linear movement of the conveyor are controlled in suchmanner that the strand or cable 110 is deposited upon the conveyor in aseries of overlapping loops as schematically illustrated. Since thereare a number of arrangements, mechanical and otherwise, that may beemployed in moving the conveyor, rotating the member 106 and propellingor imparting motion to the propellant air, it will not be necessary todisclose these in detail herein. Additionally, pneumatic and electronicarrangements are well known and available for synchronizing in anydesired ratio the movement of the conveyor, the rotation of the exittube and velocity of the fluid medium. Accordingly, these will not beillustrated or described.

In one form of carrying out the present invention, the fluid medium maycomprise air containing suspended droplets or a mist of a size material,particularly where the strand, yarn or cord is formed of an assembly ofglass subelements. Alternatively, it is frequently more desirable toapply the appropriate size material onto the deposited strand via theconduit and nozzle 126 illustrated. The size, as will be described laterherein, may serve several purposes. One is the protecting of the glassfilaments making up the strand or cord. Another is to provide a bondingeffect to the filaments, lending to the mat, when deposited thereon, anintegrity whereby the mat can be handled without falling apart.

In accordance with the present invention, it is also possible to apply asize to the strand in the manner illustrated in FIG. 6, that is, carriedby the air medium introduced through the lateral inlet tube 120, whilethe conduit nozzle arrangement 126 is employed to spray upon the loopedstrand material an elastomeric impregnant material having a compositionas described subsequently herein.

In certain cases, it is most desirable that the strand 110 introduced tothe overhead dispenser 102 already bears a size material and possiblyeven an impregnant. It is further envisioned that the conveyor 100 canbear a thin calendered sheet of rubber upon which the strand or cordmaterial is deposited in the series of overlapping loops as described.Thereafter, the rubber sheet bearing the strand material thereon in theseries of loops is combined with another calendered sheet of rubber toproduce an elongate sheet having a sandwich structure composed of outercalendered sheets of rubber and therebetween the layer of reinforcementstrand or cord in the looped configuration shown. This structure isillustrated in FIG. 7 wherein the reference numeral 130 designates alower sheet of rubber. Reference numeral 110 identifies the strand orcord in continuous looped configuration, while the reference numeral 132identifies the upper sheet of vulcanizable elastomeric rubber material.

It will be appreciated that, for purposes of clarity of illustration,the series of loops are shown with a greater spacing between therepeating loop than is present in actual practice. A closer spacing inthe drawings would obscure the pattern of the repeated loops. Usually,the cord spacing is much closer, ranging from contacting relationship tojust slightly spaced relationship with the previous course of the strandor cord. At the same time, it is frequently desirable to have the cordspaced from a half to a full cord thickness from the previouslydeposited course.

Reference numeral 140 (FIG. 7) identifies a line which constitutes thelongitudinal counterline of the continuous sheet construction. At thesame time, the character of the loop described by the deposited strandor cord is such that this same line is the situs of the plurality ofminor axis of the plurality of overlapping loops. With this arrangement,it will be further appreciated that the major axis of the plurality ofloops is transverse to the longitudinal axis 140 and extends from onelateral edge 141 to the other lateral edge 142 of the elongate sheetstructure. The elongate sheet generally identified by reference numeral145 may be bias out into appropriate lengths to form a carcass ply inthe manner of the sheet illustrated in FIGS. 3 or 4. Once so cut, thesignificance of the notations "side wall region, tread region and sidewall region" above the elongate sheet in FIG. 7 will be appreciated aswill the significance of the lines 146, 147 and 148. Line 146 coincidesgenerally with the slope of the segment of the loops within the treadregion. Line 147 coincides generally with the slopes of the segment ofthe cord or strand in the loop region falling within the side wallregion on the left of FIG. 7. Similarly, line 148 coincides with theaverage slope of that segment of the loops which lies in the side wallregion on the right of FIG. 7. Edges 141 and 145 constitute the beadforming edge of the carcass ply. Line 140, hereinabove identified as thelongitudinal axis of the sheet, also conforms to the peripheralcenterline of the tire constructed employing the carcass ply inaccordance with the structure of FIG. 7. It may be noted that the slopeof the line 146 is essentially normal to the line 140 corresponding tothe peripheral centerline. Thus, the angle of the reinforcement strandor cord 110 is essentially radial in the tread region, whereas the angleof the cord in the side wall regions is bias inclined. The inclinationof the segments as designated by the lines 147 and 148 are generallyequal and opposite. The carcass ply having a construction as illustratedin FIG. 7 is thus generally similar, in terms of the inclination of thecords in the side wall regions and the tread region, to the carcass plystructure illustrated in FIG. 3.

An elongate sheet including a flat "helix-like" disposition ofcontinuous yarn or cord in the form of a series of repeating loopstherein may also be produced by first laying down a deposition of theyarn or cord in looped disposition upon a suitable conveyor as shown inFIG. 6, preferably including a size and impregnant, followed by apassage of the so-formed mat through a four-roll rubber calender toproduce a calendered sheet having the spiral cord mat, as described,incorporated therein. It may be desirable prior to calendering to passthe looped strand mat through a heating oven to effect some securementof the looped yarn at the strand or cord crossover points to therebyincrease the structural integrity of the mat for passage through thecalendering operation. It will be appreciated that increasing the speedof the conveyor, all else remaining constant, will elongate thedimension of the loops in the direction of conveyor movement asillustrated. In this regard, reference to FIGS. 6 and 7 in combinationreveals that the minor axis of the loops (coincident with the directionof movement of conveyor 100) in the mat illustrated in FIG. 6 is lessthan the minor axis of the loops of the mat illustrated in FIG. 7. Thus,the latter is representative of either a higher conveyor speed or alower speed of angular rotation of the dispenser tube 116 and thepropellant air introduced through the lateral tube 120.

From the foregoing description in conjunction with FIGS. 6 and 7, itwill be appreciated that there is provided an extremely convenienttechnique for producing a continuous sheet in the form of a mat or inthe form of a vulcanizable elastomeric sheet containing an interior cordreinforcement; all of which structures are of utility in producing acarcass ply for tires. The disposition of the reinforcement cords interms of the angle in the several regions of the carcass may be easilychanged to meet the particular requirement of the ultimate tire. In somecases, a rather acute bias angle in the side wall region of the carcasswould be most beneficial while, in other cases, a more obtuse angle ofthe reinforcement cord in the side wall region would be most desirable.

In some circumstances, it may be desirable to sever the lateral edges141 and 142 of the elongate sheet in the course of bias cutting thesheet into carcass configuration. Thus, it will be appreciated that withthe repeated looping as described, the strand concentration is greatestat the lateral edges of the sheet in FIG. 7. In some cases, this willnot be objectionable since the buildup, due to the concentration andoverlapping in this region, will provide bulk (increased thickness) tothe carcass sheet in the ultimate bead region of the tire. On the otherhand, in certain constructions, this concentration would not bedesirable. Accordingly, as indicated, it may be desirable to sever thisedge so as to remove from 1/8 to 3/8 of an inch on each side. The biascut carcass sheet, even with the edges removed, will retain theadvantage inherent in the variable angles in the tread and side wallregions as described earlier herein.

In FIG. 8, there is disclosed a tire 150 inclusive of spaced beads 151and 152 joined by a connecting carcass 153 and having at the crownthereof a tread 154. The tire as shown is mounted in a rim 156, fittedwith a valve and stem arrangement 157 for admission of inflating air tomaintain the tire in inflated condition and the beads secured againstthe flange portions 158 of the rim. In accordance with a preferredembodiment of the present invention, the carcass of the tire includestwo carcass plies 160 and 162 which extend from bead to bead withappropriate lateral edges wrapped around the bead in conventionalfashion. The carcass plies are preferably formed of a sheet or a segmentof the length of elongate sheet material illustrated in FIG. 7 with theends bias cut and arranged in end-to-end relationship in conventionalfashion as followed in the flat band technique of tire manufacture.Since the flat band method and, as well, apparatus involved in theperformance or practice of the method are well known, the actualmanufacturing operation for the production of a tire need not bedescribed or illustrated, particularly since the method and apparatus oftire manufacture form no part of the present invention.

Referring to FIGS. 7 and 8 together, it will be appreciated that thecarcass ply in the finished tire will have the tread region of the biascut elongate sheet of FIG. 7 located in the tread region of the tire, bywhich is meant the region extending generally from shoulder to shoulder;the shoulder being identified by the reference numeral 170. Similarly,the side wall region is generally that extending from the shoulder downto the bead. This region has been identified in the plan view of theelongate sheet in FIG. 7. Comparing the two, it can be seen that thesegment of the loop in the tread region will be approaching a linenormal to the peripheral centerline of the tire while in the side wallregions, the segment of the loop therein will be inclined at an angleor, in other words, be a bias inclination. In such a disposition, thecord will extend, viewing the tire in side elevation, from the shoulderat an angle down to the bead region. A tire so constructed will thus becharacterized by a carcass of one or more carcass plies in which thecord may be described as a radial cord in the tread region and a biascord disposition in the side wall regions. It will be furtherappreciated that tires featuring carcass plies in accordance with thepresent invention may further include belt plies, breaker strips, etc.

The effectiveness of the glass as a reinforcement in the mannerdescribed herein is enhanced by treating the glass before it isincorporated into the rubber matrix. This treatment generally istwo-fold. First, the individual filaments are desirably treated with aliquid anchoring material and, secondly, the multifilament strands orcords are desirably inpregnated with an elastomeric material. Thetreatment of individual filaments with a liquid anchoring agent isperformed as individual filaments are collectively drawn from amulti-orifice platinum "bushing" containing the molten glass from whichthey are formed. Thus, the individual filaments numbering anywhere fromseveral hundred to several thousand are drawn from a plurality oforifices contained in the bottom wall of the platinum "bushing"containing the molten glass. The filaments are pulled by a windersituated below which attenuates the glass emanating from the orificesinto an extremely fine diameter. The plurality of filaments are thendrawn together into a common strand and wound on the spool. As they aredrawn together, they are sprayed with a liquid composition containing ananchoring agent, for example, an amino silane, such asgamma-propylitriethoxy silane; a mercapto substituted organoalkoxysilane; a glycidox silane, such as gamma-glycidoxypropyltrimethoxysilane; or a carboxyl group and/or unsaturated group containing silane,such as gamma-methacryloxypropyltrimethoxy silane. A Werner typecompound complexed to contain an amino, a carboxyl or other activehydrogen containing organic group may be used as the anchoring agent. Atypical size treatment composition for the glass filaments is composedof 0.5-2.0 percent by weight of gamma-aminopropyltriethoxy silane,0.3-0.6 percent by weight of a lubricant and the remainder water. Such astrand contained on the package is usually combined with a plurality oflike strands to form an ultimate yarn or cord suitable for use in thepresent invention.

The second treatment desirably given the strands or cords involves animmersion of the continuous strand or cord in a bath containing asuitable impregnant which is within a range of viscosity as will allowor favor penetration of the liquid impregnant into the strand or cord inonly a limited time of immersion. A suitable impregnant for use ineither of these application stations is composed of 60-40 parts byweight of a 38 percent dispersed solids system including abutadiene-styrene-vinyl pyridine terpolymer latex, a butadiene styrenelatex and a resorcinol-formaldehyde resin; all dispersed in 39 parts byweight of water. A commerically available product which has beenemployed as an impregnant bath in treating glass yarn and cord materialsis marketed by Uniroyal under the trade name "LOTOL 5440". Thecontinuous yarn or strand of glass bearing the impregnant is preferablythen dried in an oven, or by other suitable arrangements, to achieve apartial vulcanization and at the same time reducing the tackiness.Usually, a temperature of from 750° to 1100°F. suffices for thispurpose. The cords, of which the novel carcass ply and tireconstructions in accordance with the present invention are formed, mayinclude, in addition to glass filaments, a combined amount of an organiccomponent. Also, a composite cord construction may feature an organiccore component and a surrounding overwrap, usually spiral, of a glassstrand or yarn component. cord constructions of this type as candidatetire carcass cord members are disclosed in application Ser. Nos. 664,020filed Aug. 29, 1967; 730,139 filed May 17, 1968; and 721,688 filed Apr.16, 1968; which applications are assigned to the same assignee as thepresent application.

It will further be appreciated that carcass ply structures and tires asdescribed herein, namely, featuring differing angles in differentsegments of the ply and/or tire, may be used in combination withconventional bias ply carcass members or in combination with radial typecarcasses employed in the radial tire.

It will be appreciated from the foregoing that a variety ofmodifications are possible within the broad framework of the disclosurepresented hereinabove. Accordingly, it is intended to include all suchobvious modifications, substitutions and equivalents unless expresslyviolative of the appended claims.

I claim:
 1. The method of making a carcass ply for radial tirescomprising:moving a planar collecting surface in a generally horizontaldirection, depositing on said collecting surface a continuous length ofan elongate flexible strand comprising a gathered-together plurality ofglass filaments in repeating loops characterized in that the minor axesof said loops are coincident with the longitudinal axis of movement,whereby the central regions of said repeating loops are normal to thecentral axis of said continuously formed carcass ply of said repeatingloops conforming to the tread region of the ultimate tire, while thelateral regions conforming to the sidewall regions of the ultimate tireare characterized by an angular relationship of the strand with respectto said central axis, combining the thusly formed continuous nonwovensheet with a pair of vulcanizable elastomeric sheets coextensive in areawith the pattern of the nonwoven looped or oval-configurated depositedstrand. cutting said composite into separate segments, each having acentral tread region in which the strands are radially disposed andadjoining lateral regions in which the strands are angularly or biasdisposed, and removing marginal edges of said repeating oval, said edgesbeing characterized by a concentration of strand overlap.